Sensitizers For Dye-sensitized Solar Cells Research Articles

Fifty Shades of Phenanthroline: Synthesis Strategies to Functionalize 1,10-Phenanthroline in All Positions.

1,10-Phenanthroline (phen) is one of the most popular ligands ever used in coordination chemistry due to its strong affinity for a wide range of metals with various oxidation states. Its polyaromatic structure provides robustness and rigidity, leading to intriguing features in numerous fields (luminescent coordination scaffolds, catalysis, supramolecular chemistry, sensors, theranostics, etc.). Importantly, phen offers eight distinct positions for functional groups to be attached, showcasing remarkable versatility for such a simple ligand. As a result, phen has become a landmark molecule for coordination chemists, serving as a must-use ligand and a versatile platform for designing polyfunctional arrays. The extensive use of substituted phenanthroline ligands with different metal ions has resulted in a diverse array of complexes tailored for numerous applications. For instance, these complexes have been utilized as sensitizers in dye-sensitized solar cells, as luminescent probes modified with antibodies for biomaterials, and in the creation of elegant supramolecular architectures like rotaxanes and catenanes, exemplified by Sauvage's Nobel Prize-winning work in 2016. In summary, phen has found applications in almost every facet of chemistry. An intriguing aspect of phen is the specific reactivity of each pair of carbon atoms ([2,9], [3,8], [4,7], and [5,6]), enabling the functionalization of each pair with different groups and leading to polyfunctional arrays. Furthermore, it is possible to differentiate each position in these pairs, resulting in non-symmetrical systems with tremendous versatility. In this Review, the authors aim to compile and categorize existing synthetic strategies for the stepwise polyfunctionalization of phen in various positions. This comprehensive toolbox will aid coordination chemists in designing virtually any polyfunctional ligand. The survey will encompass seminal work from the 1950s to the present day. The scope of the Review will be limited to 1,10-phenanthroline, excluding ligands with more intracyclic heteroatoms or fused aromatic cycles. Overall, the primary goal of this Review is to highlight both old and recent synthetic strategies that find applicability in the mentioned applications. By doing so, the authors hope to establish a first reference for phenanthroline synthesis, covering all possible positions on the backbone, and hope to inspire all concerned chemists to devise new strategies that have not yet been explored.

Exploring the Role of Central Metals in Bulky Phthalocyanines for Dye-Sensitized Solar Cells.

Two series of metallo-(Zn(II), Mg(II), and Ru(II)) and free-base phthalocyanines (Pcs) with a carboxyl anchoring group and well-established bulky peripheral substituents (either tert-butyl or bulky 2,6-diisopropylphenoxy) were synthesized and tested as sensitizers in dye-sensitized solar cells (DSSCs). The trend of photovoltaic efficiencies (PCEs) for free-base and metallo Pcs followed the order Zn(II)Pc > Mg(II)Pc >> H2Pc ≈ Ru(II)Pc regardless of the peripheral substitution. Higher efficiencies (4.95 versus. 3.63 for the Zn(II) derivatives) were achieved with Pcs bearing the bulkier 2,6-diisopropylphenoxy group, indicating a lower aggregation and more suitable HOMO-LUMO levels. Furthermore, these derivatives showed a more relevant influence of the metal on the PCE (from the highest value of 4.95 for the Zn(II)Pc to the lowest value of 0.23 for the Ru(II)Pc. In both series, the best PCEs observed with the Zn(II) derivatives were mainly due to their highest Jsc values. The lowest efficiencies found for the free-bases and Ru(II) derivatives were attributed to a mismatch between their LUMO levels and the conduction band of the TiO2 and lower light-harvesting capabilities, respectively. In conclusion, Zn(II) derivatives are still the best Pc candidates to use as sensitizers in molecular photovoltaics.

Comparative study of natural and synthetic dyes in DSSCs: An experimental and computational approach

This study explores the natural and synthetic dyes as sensitizers for dye-sensitized solar cells (DSSCs). Anthocyanin dye extract (PG) from pomegranate (Punica granatum) fruit, betanin pigment (BR) from beetroot (Beta vulgaris), and the commercially available organic dye, Rose Bengal (RB), were investigated as sensitizers for DSSCs and their photovoltaic performances were recorded. Density functional theory (DFT) and time-dependent DFT (TD-DFT) studies have also been performed in order to get insight into the photophysical and photoelectrochemical properties. The overall efficiencies (η) of 0.34%, 0.30%, and 0.25% were obtained for the PG, BR, and RB dyes under 1 sun illumination, respectively. The results infer that PG dye would act as a promising photo-sensitizer for DSSCs as compared to BR and RB sensitizers, which may be due to better interaction between anthocyanin molecule of pomegranate extract and TiO2.

Poly(triphenylamine-thiazolo[5,4-d]thiazole) copolymer dyes with different anchoring end groups: Synthesis, dye-sensitized solar cell (DSSC) performance and femtosecond excited state absorption spectroscopy

In this study, the poly(triphenylaminethiazolo[5,4-d]thiazole) copolymer dyes having the different anchoring end groups of aldehyde (poly-TPATT-CHO; P5), sulfonic acid (poly-TPATT-SO3H; P5S) and cyanoacrylic acid (poly-TPATT-COOH; P5C) have been synthesized and used as sensitizers in dye-sensitized solar cells (DSSCs). The effects of the anchoring end groups of the P5, P5S and P5C copolymer dyes on the DSSC performance were examined. The synthesized copolymer dyes were characterized using 1H NMR, UV–vis. absorption and fluorescence (FL) emission spectroscopy, cyclic voltammetry (CV), MALDI-TOF-MS and FE-SEM-EDS methods. Among the studied polymers, the P5C polymer dye exhibited the best photovoltaic performance with a JSC of 6.46 mA cm−2, a VOC of 0.667 V, a FF of 0.70, and an overall power conversion efficiency (PCE) of 3.02 % under standard AM 1.5 G solar light conditions. These results are attributed to the strong binding ability of cyanoacrylic acid to the TiO2, leading to a greater photocurrent and hindered charge recombination. The effect of electron transfer mechanisms of the polymers on the DSSC performance have been investigated using the femtosecond transient absorption (fs TA) spectroscopy. The DSSC performance of the poly(triphenylaminethiazolo[5,4-d]thiazole) increased greatly by the presence of the cyanoacrylic acid anchoring end group in P5C polymer dye. The fs TA spectroscopy results revealed the presence of singlet–triplet transition for the P5C copolymer dye, while the P5 and P5S copolymers showed only singlet–singlet transitions. The observed triplet state transition in the P5C polymer increased the yield of the DSSC system.

Natural extracts from Rhus microphylla and Opuntia joconostle as mono and co-sensitizers for efficiency enhancement of nano-TiO2 based dye-sensitized solar cells

In this work, six plants are presented to obtain different molecules with distinct properties to be used in dye-sensitized solar cells (DSSC). Cells have been assembled using Opuntia joconostle (xoconostle), Rhus microphylla (limilla), Tagetes erecta (marigold flower), Euphorbia pulcherrima (poinsettia flower), Bougainvillea spectabilis (bougainvillea) and Camellia sinensis (green tea) as individual and mixed pigments. In the case of xoconostle and limilla this is the first time that their extracts have been used as sensitizers in DSSC. Having these natural dyes, the co-sensitization technique was adopted to improve the photovoltaic performance of the solar cells. The best performance with the individual extracts was from the poinsettia flower having a conversion efficiency of 0.0022 % with Voc of 0.29 V, Jsc of 0.014 mA/cm2 and FF of 48.56, in the case of co-pigmentation, the best mixture was poinsettia flower with xoconostle and green tea (NXT) having a conversion efficiency of 0.0044 % with Voc of 0.34 V, Jsc of 0.035 mA/cm2 and FF of 44.50, using irradiation of 1000 W/m2 at 25°C. The purpose of mixed dyes is to absorb a wider interval of the electromagnetic spectra. Computational calculations based on the Density Functional Theory were used to calculate each molecule’s HOMO and LUMO levels.

Use of new natural dyes extracted from different sections of Salvia urica in dye-sensitized solar cells

In this study, natural dyes that were obtained from the branches, flowers and leaves of Salvia urica were utilized as sensitizers in TiO2-based dye-sensitized solar cells (DSSCs). XRD and FE-SEM were used to analyze the crystal structure and morphological properties of the produced TiO2 nanopowders, respectively. The optical properties of natural dyes extracted from the Salvia urica plant were investigated by UV-vis spectroscopy. Functional groups in natural dyes were detected by FTIR spectroscopy, while DSSCs were evaluated for photovoltaic performance and electrochemical impedance. The findings show that the flower dye absorbs a wider wavelength of light in the visible region and the interaction between the carbonyl/hydroxyl groups and the TiO2 surface is very strong, which is why it is the most efficient way of power conversion among all other natural sensitizers. The efficiencies of DSSCs sensitized with flower, branch and leaf dye of Salvia urica were 0.33%, 0.28%, and 0.19%, respectively.

The Effect of Position of Cyano-3-Acetic Acid Electron Withdrawing Group on γ-Mangostin as a Sensitizer on Dye-Sensitized Solar Cells (DSSC): Theoretical Study

Computational research on the influence of the electron acceptor group position of cyano-3-acetic acid on γ-mangostin as a sensitizer in Dye-Sensitized Solar Cell (DSSC) has been carried out with variations in the positions of the atoms O-1, O-2, O-3 and O- 4. The photoelectric properties are known from the HOMO-LUMO energy parameters, UV-Vis absorption, |VRP|, ΔGinject, ΔGreg, τ, LHE and FEDAM. Geometry optimization uses Orca 4.2.1 with a 6-31G* basis set and interpretation uses Avogadro, Chemissian and GaussSum. Ground state optimization uses the DFT-B3LYP method and excited state optimization uses the TD-DFT-B3LYP method. The results showed that the difference in photoelectric properties affected the DSSC performance. O-2 has the best parameters for electron scattering and UV-Vis light with an absorption of 426 nm. O-3 has the best value for excited state lifetime (τ) and coupling constant (|VRP|). O-3 has a weakness in the LHE value. The LHE value for compounds without modification has the best value. Based on the qualitative parameters of the Full-Electron Donor-Acceptor Map (FEDAM) it was found that the ability of cyano-3-acetic acid as an electron acceptor is better at O-2.

Biodiesel production from the Scenedesmus sp. and utilization of pigment from de-oiled biomass as sensitizer in the dye-sensitized solar cell (DSSC) for performance enhancement

Dye-sensitized solar cell (DSSC) using algal photosynthetic pigments has got rampant attention as it converts sunlight into electricity. Therefore, in this present research, the neutral lipid extracted from the green alga Scenedesmus sp. was used for biodiesel production, and concurrently, pigments extracted from the de-oiled biomass cake were used as a sensitizer in DSSC to evaluate its performance efficacy with and without PVDF (Polyvinylidene fluoride). Initially, neutral lipids extracted from the Scenedesmus sp. were converted to biodiesel with a yield of 72.9%, and the de-oiled biomass was subjected to pigment extraction (17.65 mg/g) to use as a sensitizer in DSSC. This study proposes two DSSC test models, i.e., PVDF (Polyvinylidene fluoride) - bound cell and cell without any PVDF binder. For the PVDF-coated DSSC, the average energy conversion efficiency reached about 14.3%, the open circuit voltage was 0.55 V, and the short circuit current was 144.5 mA. The unbound cells showed a reduction in efficiency, voltage, and current, and notably efficiency of 10.44% on day 1 was decreased to 3.32%, and the open circuit voltage and short circuit current of 0.38V and 144mA were decreased to 0.24V and 130 mA after 10 days, under 40 mW/cm2 input power. The PVDF-coated solar cell has maintained its efficiency range of 16.32%–11.22%, which is higher than the PVDF-unbound cell for a tested timeline of 30 days. The fill factor of 0.47 was observed in PVDF- unbound DSSC under 40 mW/cm2 as input power, while it was increased to 0.577 when PVDF was used as a binder. The PVDF-coated cell has low degradation compared with the PVDF-uncoated cell. These results offer dual benefits as the production of biodiesel from microalgal lipids and electricity generation from the DSSC using the pigments of biodiesel-extracted algal biomass.

5-(9-(p-Tolyl)-2,3,4,4a,9,9a-hexahydro-1H-1,4-methanocarbazol-6-yl)thiophene-2-carbaldehyde

Donor–π spacer–acceptor (D–π–A) dyes are among the most attractive structures for the design of organic dye-sensitized solar cells (DSSCs). Typically, the key intermediates for these sensitizers are D–π compounds containing an aldehyde group to which an anchor acceptor group is attached via the Knoevenagel reaction. In this communication, 5-(9-(p-tolyl)-2,3,4,4a,9,9a-hexahydro-1H-1,4-methanocarbazol-6-yl)thiophene-2-carbaldehyde was prepared via the Suzuki cross-coupling reaction. The structure of the newly synthesized compound was established by means of high-resolution mass spectrometry, 1H NMR, 13C NMR, IR, and UV–Vis spectroscopy. The title compound would be used in the synthesis of sensitizers for DSSCs.

Steric Effects on the Photovoltaic Performance of Panchromatic Ruthenium Sensitizers for Dye-Sensitized Solar Cells.

Three new heteroleptic Ru complexes, CYC-B22, CYC-B23C, and CYC-B23T, were prepared as sensitizers for coadsorbent-free, panchromatic, and efficient dye-sensitized solar cells. They are simultaneously functionalized with highly conjugated anchoring and ancillary ligands to explore the electronic and steric effects on their photovoltaic characteristics. The coadsorbent-free device based on CYC-B22 achieved the best power conversion efficiency (PCE) of 8.63% and a panchromatic response extending to 850 nm. The two stereoisomers, CYC-B23C and CYC-B23T coordinated with an unsymmetrical anchoring ligand, display similar absorption properties and the same driving forces for electron injection as well as dye regeneration. Nevertheless, the devices show not only the remarkably distinct PCE (6.64% vs 8.38%) but also discernible stability. The molecular simulation for the two stereoisomers adsorbed on TiO2 clarifies the distinguishable distances (16.9 Å vs 19.0 Å) between the sulfur atoms in the NCS ligands and the surface of the TiO2, dominating the charge recombination dynamics and iodine binding and therefore the PCE and stability of the devices. This study on the steric effects caused by the highly conjugated and unsymmetrical anchoring ligand on the adsorption geometry and photovoltaic performance of the dyes paves a new way for advancing the molecular design of polypyridyl metal complex sensitizers.

Computational Studies of Suitability of Triarylmethane-Coumarins as Sensitizer for Dye-Sensitized Solar Cells

Triarylmethanes are low cost synthetic dyes with intense absorption in the visible spectrum. This make it attractive to explore their suitability as sensitizer for dye sensitized solar cell. Using malachite green as a lead dye, we made intuitive structural modifications: incorporation of coumarin-3-carboxylic acid as acceptor/anchor, and substituting one or the two N, N-diethylaniline donors with N-propyl-1,6dimethyllutidine(s). The three resulting triarylmethane-coumarin structures were subjected to DFT calculations to investigate their suitability as sensitizers for DSSC applications. The calculation results showed that triarylmethane-coumarins with cationic type chromophores are unsuitable as DSSC sensitizer. The acceptor/anchor, coumarin-3-carboxylic acid, is basically excluded in the intramolecular charge transfer processes of the cationic dyes. Also, the LUMO levels of the cationic dyes are below the conduction band of TiO2, which is energetically uphill to electron injection into TiO2. Ultimately, the cationic triarylmethane-coumarin derivatives are unsuitable as sensitizer for DSSC. However, a charge-free triarylmethane-coumarin derivative shows promise as a sensitizer candidate for DSSC application.

Acridine-based metal-free organic dyes with various auxiliary acceptors for dye-sensitized solar cells

Two new metal-free organic dyes containing triphenylamine as a donor, acridine as a π-bridge, cyanoacrylic acid as an anchoring group and a different auxiliary acceptor benzothiadiazole or N-propylbenzotriazole have been synthesized and used as sensitizers in dye-sensitized solar cells (DSSCs). The effect of auxiliary acceptors on the performance of the DSSCs was investigated by optical, electrochemical, theoretical, and photovoltaic methods. The DSSC based on BIM26 containing N-propylbenzotriazole shows power conversion efficiency (PCE) of 4.55%, much higher than that of BIM25 containing benzothiadiazole (3.76%) under simulated AM 1.5G solar irradiation. When co-adsorbed with CDCA, BIM25 exhibits a larger improvement in the photovoltaic performance (PCE = 5.59%) in comparison to BIM26 (PCE = 5.56%). The co-sensitization of BIM26 with a long absorption wavelength metal-free dye C1 further improves the PCE to 6.48%. These results demonstrate that the acridine based-dye with a N-propylbenzotriazole can be used not only as a single sensitizer to inhibit aggregation and charge recombination but also as a co-sensitizer to enhance light-harvesting ability.

Impact of π-spacer on dye-sensitized solar cells and non-linear optical performance: Styryl vs imine vs azo

Julolidine-based dyes, having a benzoic acid anchoring group, conjugated through different π-bridges (styryl, imine, and azo) have been investigated. It is discovered that the charge transfer (CT) characteristics of the dye system are changed as the π-bridges become less symmetrical. According to TD-DFT studies, the vertical absorption maximum shifts to the red region when the “N” atom is added to the styryl backbone. Computed photovoltaic characteristics, however, indicate that these dyes perform poorly when the “N” atom is added to the styryl backbone. Studies on dye@TiO2 clusters showa possible bonding between these dyes and TiO2, which would cause dye@TiO2 cluster absorption to shift red. Conversely, computed results of linear and non-linear optical (NLO) properties exhibit opposite patterns to those observed in dye-sensitized solar cell (DSSC) performance.Julolidine-based dyes with imine and azo linkers combined with benzoic acid were created and evaluated as DSSC sensitizers to determine their practical application. In agreement with DFT findings, experimental absorption in dimethylformamide (DMF) and cyclic voltammetry (CV) study verified the essential need for HOMO and LUMO energy levels. High thermal stability is indicated by the thermogravimetric analysis (TGA) results, which supports practical applications in DSSCs and non-linear optics (NLO). The efficiency patterns of the fabricated DSSC cells were similar, with JNNC showing the lowest efficiency (0.07 ± 0.02) and JCNC-OH demonstrating the highest (1.94 ± 0.02).

Novel cyano functional small molecule photosensitizers with amplified electron injection and photovoltaic attributes: molecular modelling towards efficient dye‐sensitized solar cells

AbstractBACKGROUNDThe exploration of novel photosensitizers with reverberant optoelectronic features for dye‐sensitized solar cells (DSSCs) is a frontline area of research. In this respect, attempts have been made to design a series of novel organic dyes (JFK‐1–JFK‐10) with D‐π‐A framework by π‐spacer modification strategy. The suitability of developed sensitizers for DSSCs applications is confirmed by executing natural bond orbital (NBO) analysis, transition density matrix (TDM) analysis, frontier molecular orbital (FMO) analysis, density of state (DOS) analysis, binding energy (Eb), electron regeneration energy (ΔGreg), free energy of injection (ΔGinject), electronic coupling constant (VRP), and intramolecular charge transfer (ICT) parameters qCT (e‐), DCT (Å), H index (Å), ∆(Å), t index (Å), μCT (D).RESULTSThe calculated results of these analyses show that replacing the thiophene (B0) π‐spacer with extended conjugated thiazole and thiophene as a π‐spacer (B1‐B10) results in significantly lowered FMO energy levels, broader λmax values, and ICT parameters respectively. All the proposed dyes could be used as excellent sensitizers for DSSCs; the B9 spacer in JFK‐9 makes JFK‐9 a highly efficient candidate for the high‐efficiency of DSSCs due to promising photovoltaic characteristics, like the reduced Egap (4.386 eV), longer λmax(427.989 nm), longer excited state lifetimes (1.483 ns), a lower ΔGreg (1.807 eV), a greater dipole moment of (9.475 D), and large qCT (0.546), LHE (0.981), and eVOC (1.729 eV).CONCLUSIONThe fabricated dyes’ (F1‐F9) photoelectronic and chemical transfer parameters near the titania‐electrolyte interface (dyes@TiO2) proved have better accumulation and recombination of dyes@TiO2 model. The adsorption energies calculated of all compounds provide a deep insight into adsorption and charge transfer to a semiconductor TiO2 conduction band. Hence, these modeled dyes (JFK‐1‐JFK‐10) could be used as efficient DSSCs and open new avenues for researchers to synthesize high‐performance DSSCs. © 2024 Society of Chemical Industry (SCI).

New natural dyes extracted by ultrasonic and soxhlet method: Effect on dye-sensitized solar cell photovoltaic performance

This study employed soxhlet and ultrasonic methods to extract novel natural dyes from Rhamnus tinctoria seed, Rubia fruticosa fruits, and Pinus pinea bark, which were then used as sensitizers in dye-sensitized solar cells (DSSCs). XRD data showed that TiO2 in the photoanode layer was in the anatase phase. The produced DSSCs were assessed for photovoltaic performance and electrochemical charge transfer while sensitizing dyes were characterized using UV–vis spectroscopy and FTIR. Natural dyes leached with different extraction methods showed different absorption behaviors in the UV–vis region. FTIR results revealed the presence of both carbonyl and hydroxyl groups, which enhanced the interaction between the extracted dyes and the TiO2 thin film. All cells using sensitizers obtained by the Soxhlet method showed higher efficiency compared to the ultrasonic method. The highest cell performance (ɳ = 0.47%) was obtained with 0.71 V Voc, 0.92 mA/cm2 Jsc, and 0.72 FF for the sensitizer extracted from Rhamnus tinctoria seeds by the soxhlet method.

Preliminary study: Potency metal complexes with UV-active ligands as dye sensitizer in Dye Sensitized Solar Cells

The use of metal complexes as a dye sensitizer in DSSC (Dye-Sensitized Solar Cells) provides many promising opportunities. Complex compounds with ligands that actively absorb UV rays have the potential to be applied in technology solar cells in areas rich in UV rays such as Indonesia. This research aim is to investigate the potential of several complex compounds with UV active ligands and apply them as dye sensitizer in DSSC. Ligand phenanthroline (phen), and morin will be synthesized with several transition metals. The synthesized metal complexes were characterized by spectrophotometer UV-VIS (for all metal complexes) and spectrophotometer FTIR (for morin complexes). The performance of metal complexes as dye sensitizer will be analyzed from the current and voltage obtained and in this research was limited to the phenanthroline complex compound because the research was still in the ongoing process. The highest current produced by [Ni(phen)3]2+ with 0.452 mA while the highest voltage produced by complex [Fe(phen)3]2+ with 711 mV.

Performance of complex compound Zn-TPP (5,10,15,20-tetrafenylporphyrin) as a dye sensitizer in increasing the current and voltage of dye sensitized solar cells

Solar cell technology has been widely used, one of them is Dye Sensitized Solar Cell (DSSC), which is a semiconductor device that can convert sunlight into electrical energy. The objective of this research is to learn the character of metal complexes from derivatives porphyrin Zn-TPP (5,10,15,20-tetraphenylporphyrin) and apply it as a dye sensitizer in DSSC. Zn(II)-TPP complex compound showed a maximum wavelength at 423 nm on the Soret band. Zn-N bond formed between metal and ligand is indicated at 324,04 cm-1. Zn (II)-TPP complex compound is ionic and best used in DSSC applications. The performance (efficiency) of Zn (II)-TPP complex as dye sensitizer in DSSC shows a maximum current of 8 mA/cm2 with a maximum voltage of 0.60 V and an efficiency value of 9.43%.

Natural dyes for dye-sensitized solar cells (DSSCs): An overview of extraction, characterization and performance

Dye-sensitized solar cells (DSSCs) have emerged as a promising technology for solar energy conversion due to their affordability and adaptability. Natural dyes derived from various botanical and fruit sources are gaining attention as an eco-friendly alternative to synthetic counterparts in DSSCs. This comprehensive review offers insights into the extraction techniques, characterization methods and effectiveness of natural dyes as sensitizers in DSSCs. Moreover, it examines the variables impacting the efficiency of DSSCs using natural dyes and investigates strategies to enhance their overall performance. By presenting this comprehensive overview, the paper aims to underscore the viability of natural dyes for DSSCs, promoting continued exploration and advancement in this area of research.

Fabrication of efficient natural dye-sensitized Solar Cells using Mediterranean olive leaves as natural dye sensitizer

The synthesis of synthetic dyes employed in dye-sensitized solar cells (DSSCs) is often associated with substantial costs and environmental concerns. As a result, there is growing interest in utilizing natural dyes as sensitizers for DSSCs. This paper presents a comprehensive investigation into the extraction of natural dyes from Mediterranean olive leaves using a methanol-based solution, with a particular focus on the impact of different drying times during the dye extraction process on the efficiency of fabricated solar cells. The extracted olive leaf dyes were systematically characterized, encompassing their optical properties analyzed through ultraviolet–visible (UV–Vis) and Fourier Transform Infrared (FTIR) spectroscopy, electrochemical behavior, photovoltaic performance, crystallographic and morphological structures, as well as elemental composition. The research findings unveiled distinctive attributes of the olive leaf dyes, attributable to variations in their charge transfer processes to the band edge of the TiO2 semiconductor. These outcomes were substantiated through comprehensive analyses involving UV–Vis, FTIR, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Notably, the olive leaf dye subjected to a longer drying time (referred to as OLDS1) exhibited an energy level of the lowest unoccupied molecular orbital (LUMO) closer to that of the conduction band of TiO2, facilitating efficient electron transfer. Furthermore, X-ray photoelectron spectroscopy revealed alterations in elemental composition upon dye adsorption onto the TiO2 surface, with a notable reduction in the intensities of the Ti 2p and O 1 s peaks. The OLDS1 dye demonstrated lower charge transfer resistance and recombination rates compared to the shorter drying time for both fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO)-based natural DSSCs (NDSSCs). Importantly, the choice of substrate material, specifically FTO and ITO, significantly influenced the NDSSC performance. The FTO/TiO2/OLDS1 configuration exhibited remarkable characteristics, including a high fill factor (FF) of approximately 0.73 and an efficiency of 0.31 %, accompanied by a short-circuit current density of 0.662 mA/cm2 and an open-circuit voltage of 0.642 V. These results highlight the crucial role of drying time and substrate selection in the fabrication of NDSSCs utilizing Mediterranean olive leaf extracts, with the FTO/TiO2/OLDS1 configuration emerging as the most promising and efficient combination.

Deep-learning-assisted photovoltaic performance prediction of sensitizers in dye-sensitized solar cells

A deep learning model is established to predict the photovoltaic performance of sensitizers in dye-sensitized solar cells.